A compromising move, since now Black can capture on f3 and weaken the pawn structure. The problem for White is that there's no active plan. If the knight on f4 is captured, then the g-file is opened, and the attack becomes very strong.
16... g4h5 A useful move to prepare g5-g4 or get the bishop to g6. 17. c4f1  17... c8b8 This move is always useful. 18. a1d1  18... h8e8 